<form class='form-horizontal'>
  <div id='reactContainer'/>

  <script cam-script type='text/form-script'>
    const container = document.getElementById('reactContainer');

    const e = React.createElement;

    class InputGroup extends React.Component {
      render() {
        return e('div', {className: 'form-group'}, [
          e('label', {className: 'control-label col-md-4', key: 'label'}, this.props.label),
          e('div', {className: 'col-md-6', key: 'input field'}, [
            this.props.children,
            e('div', {className: 'help-block', key: 'help label'}, this.props.helpText)])
          ]);
      }
    }

    class StartForm extends React.Component {
      constructor(props) {
        super(props);
        this.state = {
          creditor: '',
          amount: '',
          category: 'Travel Expenses',
          invoiceID: ''
        };

        this.fileInput = React.createRef();

        this.handleInputChange = this.handleInputChange.bind(this);
        this.handleSubmit = this.handleSubmit.bind(this);
        this.handleFileUpload = this.handleFileUpload.bind(this);
        // Register submit
        camForm.on('submit', evt => {
          this.handleSubmit(evt);
        });
      }

      handleFileUpload(event) {
        const reader = new FileReader();
        reader.readAsDataURL(this.fileInput.current.files[0]);
        reader.onload = () => {this.setState({invoiceDocument: reader.result.replace(/^data:(.*;base64,)?/, '')})};
        reader.onerror = error => {console.error(error)};
      }


      handleInputChange(event) {
          const value = event.target.value;
          const name = event.target.name;

          this.setState({
            [name]: value
          });
        }

      handleSubmit(event) {
        camForm.variableManager.createVariable({
          'name': 'invoiceDocument',
          'type': 'File',
          'value': this.state.invoiceDocument,
          'valueInfo': {filename: 'invoice.pdf'},
          isDirty: true}
        );
        camForm.variableManager.createVariable({
          'name': 'creditor',
          'type': 'String',
          'value': this.state.creditor,
          isDirty: true}
        );
        camForm.variableManager.createVariable({
          'name': 'amount',
          'type': 'Double',
          'value': this.state.amount,
          isDirty: true}
        );
        camForm.variableManager.createVariable({
          'name': 'category',
          'type': 'String',
          'value': this.state.category,
          isDirty: true}
        );
        camForm.variableManager.createVariable({
          'name': 'invoiceID',
          'type': 'String',
          'value': this.state.invoiceID,
          isDirty: true}
        );
      }

      render() {
        return e('div', {className: 'form-group'}, [
          e(InputGroup, {label: 'Invoice Document: ', key: 'InvoiceDocument'},
            e('input', {
              className: 'form-control',
              name: 'invoiceDocument',
              type: 'file',
              ref: this.fileInput,
              onChange: this.handleFileUpload})),
          e(InputGroup, { label: 'Creditor: ',
                          helpText: 'e.g. "Super Awesome Pizza"',
                          key: 'Creditor'},
            e('input', {
              className: 'form-control',
              name: 'creditor',
              type: 'text',
              onChange: this.handleInputChange,
              value: this.state.creditor})),
          e(InputGroup, { label: 'Amount: ',
                          helpText: 'e.g. "30.00"',
                          key: 'Amount'},
            e('input', {
              className: 'form-control',
              name: 'amount',
              type: 'number',
              onChange: this.handleInputChange,
              value: this.state.amount})),
          e(InputGroup, { label: 'Invoice Category: ',
                          key: 'Category'},
            e('select', {
              className: 'form-control',
              name: 'category',
              value: this.state.category,
              onChange: this.handleInputChange
            }, [
              e('option', {value: 'Travel Expenses', key: 'Travel'}, 'Travel Expenses'),
              e('option', {value: 'Business Meals', key: 'Meals'}, 'Business Meals'),
              e('option', {value: 'Other', key: 'Other'}, 'Other'),
            ])),
            e(InputGroup, {label: 'Invoice Number: ',
                          helpText: 'e.g. "I-12345"',
                          key: 'InvoiceNumber'},
              e('input', {
                className: 'form-control',
                name: 'invoiceID',
                type: 'text',
                onChange: this.handleInputChange,
                value: this.state.invoiceID})),
        ]);
      }
    }

    const root = ReactDOM.createRoot(container);
    root.render(e(StartForm));
  </script>
</form>
